A child merge that came back blocked/verify_failed/untracked_collision during a
parent/children unit merge used to vanish: DrainAsync only logged it server-side,
PlanningMergeAborted carried no reason, and ApproveReview/review_task always
reported StatusMerged for a task with children regardless of the real outcome,
so a failed unit merge left the parent stuck with no visible error.
- PlanningMergeOrchestrator.StartAsync/ContinueAsync/DrainAsync now return a
PlanningMergeResult(Status, Reason) instead of void, and PlanningMergeAborted
carries that reason to the UI.
- WorkerHub.ApproveReview and ExternalMcpService.ReviewTask's approve branch
propagate the real status/reason for a parent with children instead of
hardcoding "merged" (or masking a non-conflict failure as "conflict").
- StartAsync now requires the parent to already be WaitingForReview for
improvement parents too, not just planning ones, so a stale caller can no
longer trigger a partial child merge.
- HasActiveMerge now also covers the window between the last child merging and
FinalizeParentDoneAsync completing, closing a gap where a concurrent Cancel
could race the parent's own approve-to-Done transition.
- IslandsShellViewModel.OnPlanningMergeAborted flashes the reason via
FlashFooterError instead of only clearing the external-merge banner.
mika kuns
f205843020